A method is disclosed in Japanese Patent Publication SHO 46(1971)-13636 which produces a shaped article. The method involves placing the electrodepositing liquid in an electrodepositing tank provided with at least one cathode and at least one anode and applying electric potential between the two electrodes mentioned above thereby causing the fibrous substance in the electrodepositing liquid to be accumulated on either of the two electrodes. In this case, the accumulation of the fibrous substance and the consequent formation of the shaped article occur on the surface of the cathode when the pH value of the electrodepositing liquid is adjusted below 6 or on the surface of the anode when the pH value is adjusted above 9.
A known apparatus for the electrodeposition of a fibrous protein has been disclosed which is comprised of an electrodepositing tank, one tubular electrode disposed along the inner wall of the electrodepositing tank, and one other tubular electrode disposed along the inner wall of the first tubular electrode, and serving the purpose of allowing the aforementioned fibrous protein to be deposited in the shape of a tubular layer in a freely extractable manner on the outer periphery of the inner electrode. This apparatus is characterized by providing two stirring devices adapted to rotate in mutually opposed directions, one in the upper region and the other in the lower region respectively of the annular space separating the inner and outer tubular electrodes. This apparatus is described in Japanese Unexamined Utility Model Application SHO 56(1981)-170232.
When a shaped article is obtained from one kind of electrodepositing liquid by the use of one electrodepositing tank as described above, however, the properties of the shaped article produced in a single layer are substantially determined by the properties of the fibrous substance. By using the apparatus described above, there can be obtained an electrodeposited film wherein the fibrous substance is oriented in different directions in the inner surface region and the outer surface region of the film. This film nevertheless is a single-layer product physically. With this apparatus, therefore, it is difficult to give any noticeable alteration to the properties of the single-layer product. When the shaped article is produced in the form of a laminate, this shaped article acquires properties which cannot be expected from a comparable single-layer product. In the case of a sausage casing which is obtained in the form of a laminate by using as fibrous substances two dissimilar electrodepositing liquids, one containing an enzymatically treated fibrous collagen and the other containing an untreated fibrous collagen, for example, when this sausage casing is packed with meat, smoked, and prepared for ready consumption, the presence of the casing arouses absolutely no objectionable sensation to the mouths of those who eat the sausage. This casing cannot be obtained by the conventional method which is directed to the manufacture of a single-layer sausage casing.
As concerns the concept of forming a laminate by partitioning the interior of the electrodepositing tank and feeding two or more dissimilar electrodepositing liquids one each into the separated sections of the tank, an apparatus constructed as illustrated in FIG. 1 and a method for the manufacture of a laminate by the use of this apparatus are disclosed in U.S. patent application Ser. No. 448,569, now abandoned, filed on Dec. 10, 1982 by the present applicants.
In the apparatus illustrated in FIG. 1, reference numeral 1 denotes an electrodepositing tank which is separated with partitions 8, into a plurality of chambers. 2 denotes an inner electrode and 3 an outer electrode. Between the two electrodes, a diaphragm 4 is supported in position by a diaphragm holder 5. An aqueous suspension of a fibrous substance possessing an electrophoretic charge is introduced via feed pipes 9, 9', 9" into an inner electrode chamber 6 defined by the aforementioned diaphragm and an electrode liquid is introduced via a feed pipe 13 into an outer electrode chamber 7. The aforementioned partitions 8 which are spaced by intervals enough to avoid inflicting any injury to the film of fibrous substance formed by electrodeposition between the outer and inner electrodes are attached to the aforementioned diaphragm holder 5. Further, 10, 10' denotes discharge tubes for liquid, 11, 11', and 11" overflow receptacles, and 12, 12' stirring blades which are operated by motors 15, 16.
This apparatus, however, has inevitably entailed the disadvantage that the dissimilar electrodepositing liquids being introduced into the plurality of separated chambers will intermingle with one another at the partitions 8.